The general purpose of this project is to investigate the movements of the articulatory structures during speech production primarily by use of high-speed cinefluorographic techniques. Studies will be designed to obtain basic data on the articulatory characteristics of consonant and vowel sounds of American English and to determine the timing interrelationships between various articulatory movements. Variations in articulatory characteristics and relationships will be studied as a function of such factors as phonetic environment, stress, rate of utterance, and the position of boundaries between syllables, morphemes, or larger linguistic units. Such data will be utilized to more accurately specify on a systematic basis the dynamic properties of speech articulation and the constraints on articulatory movements for speech. An attempt will be made to relate the findings to theoretical models of the organization of the speech articulatory processes.